The embodiments described herein relate to apparatus, methods, and systems for retaining a cable, such as a cable having an inner conductor and an outer conductor. The inner conductor of such cables is generally surrounded by a dielectric material. The dielectric material is typically surrounded by the outer conductor, for example, a conducting braid. More specifically, some embodiments described herein are suitable for coupling, to a printed circuit board, a coaxial cable operable to transmit high- and/or radio-frequency signals.
Known methods for coupling cables to printed circuit boards include using connectors, such as a U.FL connector. Such connectors, however, typically induce discontinuities in the signal path. For example, such connectors are typically mounted at a right-angle to the printed circuit board. Such signal path discontinuities can compromise the high-frequency performance of such connectors. U.FL connectors, for example, may not be suitable for signals exceeding 3 GHz.
Alternatively, cables can be soldered directly to printed circuit boards. In the case of a radio assembly the cable becomes part of the assembly for calibration purposes. Such cables are generally prepared for shipping and/or use by cutting the cable such that a portion of the dielectric extends beyond the outer conductor, and a portion of the inner conductor extends beyond the dielectric material. Before use, the inner conductor and/or the outer conductor can be dipped in solder to prevent fraying. Traditionally, an axial length of the dielectric material provides electrical insulation between the inner conductor and the outer conductor. Without an axial length of dielectric, the solder used to prevent fraying could electrically couple the outer conductor to the inner conductor. Having a portion of dielectric material extending axially beyond the outer conductor, however, can cause series inductance and/or shunt capacitance, which can decrease high-frequency performance of the cable. A need therefore exists for apparatus, methods, and systems for retaining a coaxial cable on a printed circuit board suitable for high-frequency applications.